Don't update bestValue in check_is_dangerous()

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index d4826946fb043b98b5e8ec4cc2d77d1e0e5315d8..e53baabd98903430ae37bdc78d4bf64e3e4525bf 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -130,7 +130,7 @@ namespace {
   Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
 
   void id_loop(Position& pos);
-  bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue);
+  bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta);
   bool connected_moves(const Position& pos, Move m1, Move m2);
   Value value_to_tt(Value v, int ply);
   Value value_from_tt(Value v, int ply);
@@ -1279,7 +1279,7 @@ split_point_start: // At split points actual search starts from here
           &&  move != ttMove
           && !pos.is_capture_or_promotion(move)
           &&  ss->eval + PawnValueMidgame / 4 < beta
-          && !check_is_dangerous(pos, move, futilityBase, beta, &bestValue))
+          && !check_is_dangerous(pos, move, futilityBase, beta))
           continue;
 
       // Check for legality only before to do the move
@@ -1330,20 +1330,19 @@ split_point_start: // At split points actual search starts from here
   // bestValue is updated only when returning false because in that case move
   // will be pruned.
 
-  bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bestValue)
+  bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta)
   {
     Bitboard b, occ, oldAtt, newAtt, kingAtt;
-    Square from, to, ksq, victimSq;
+    Square from, to, ksq;
     Piece pc;
     Color them;
-    Value futilityValue, bv = *bestValue;
 
     from = from_sq(move);
     to = to_sq(move);
     them = ~pos.side_to_move();
     ksq = pos.king_square(them);
     kingAtt = pos.attacks_from<KING>(ksq);
-    pc = pos.piece_on(from);
+    pc = pos.piece_moved(move);
 
     occ = pos.occupied_squares() & ~(1ULL << from) & ~(1ULL << ksq);
     oldAtt = pos.attacks_from(pc, from, occ);
@@ -1361,23 +1360,13 @@ split_point_start: // At split points actual search starts from here
 
     // Rule 3. Creating new double threats with checks
     b = pos.pieces(them) & newAtt & ~oldAtt & ~(1ULL << ksq);
-
     while (b)
     {
-        victimSq = pop_1st_bit(&b);
-        futilityValue = futilityBase + PieceValueEndgame[pos.piece_on(victimSq)];
-
         // Note that here we generate illegal "double move"!
-        if (   futilityValue >= beta
-            && pos.see_sign(make_move(from, victimSq)) >= 0)
+        if (futilityBase + PieceValueEndgame[pos.piece_on(pop_1st_bit(&b))] >= beta)
             return true;
-
-        if (futilityValue > bv)
-            bv = futilityValue;
     }
 
-    // Update bestValue only if check is not dangerous (because we will prune the move)
-    *bestValue = bv;
     return false;
   }
 
@@ -1865,7 +1854,7 @@ void Thread::idle_loop(SplitPoint* sp_master) {
           lock_grab(Threads.splitLock);
 
           assert(is_searching);
-          SplitPoint* sp = splitPoint;
+          SplitPoint* sp = curSplitPoint;
 
           lock_release(Threads.splitLock);
 
@@ -1906,9 +1895,6 @@ void Thread::idle_loop(SplitPoint* sp_master) {
               Threads[master].wake_up();
       }
   }
-  // In helpful master concept a master can help only a sub-tree of its split
-  // point, and because here is all finished is not possible master is booked.
-  assert(!is_searching);
 }